The aim of this program project is to evaluate a high magnetic field strength clinical NMR imaging spectrometer. The apparatus may be operated at 15kG, thus permitting the imaging of protons, sodium and phosphorus. The clinical evaluation will be carried out on cancer patients with the confirmed diagnosis or strongly suspected diagnosis of a malignant neoplasm with poor prognosis. The research involves physical experiments to optimize imaging parameters and develop methodology for calibration and quality control of this new modality. In vitro NMR experiments are planned on resected tissues to permit a correlation between the clinical images and actual measurements obtained directly from the resected tissues. The clinical correlations are between x-ray CT and NMR images obtained at similar anatomical levels for both proton and sodium nuclei. It is hoped that this modality will provide unique information about tissue characteristics in vivo, thus increasing the probability of noninvasively reaching a specific diagnosis. The safety of this new modality will be studied at the systemic level and at the cellular level. We hope to correlate the biological hazards of NMR and ionizing radiation. Blood flow measurement will be carried out noninvasively using the clinical NMR spectrometer in the carotid artery in the neck and in cross-sections of the brain. We will study the optimal NMR imaging technique, image artifacts and reconstruction algorithms on an off-line satellite computer. The study of phosphorus in the human body will be carried out in selected areas of normal and pathological human tissue nonivasively, in a clinical setting, with correlation with animal results.